The present invention relates to a method and apparatus for loading and unloading tape from a removable tape cartridge in a tape drive.
Single reel tape cartridges are used to transport and store tape for reel-to-reel tape drives. A single reel tape cartridge is inserted into a tape drive and a mechanism is used to load the end of the tape into a take-up reel from the tape cartridge. Once the end of the tape is loaded into the take-up reel, the tape drive operates as a reel-to-reel tape drive. A motor is coupled to the take-up reel to rotate the take-up reel about the take-up reel axis and another motor is coupled to the single reel tape cartridge to rotate the reel of the tape cartridge about its axis.
The tape drive loading mechanism attaches to a tape leader pin, located at the end of the tape contained in the single reel tape cartridge. The hub filler uses a slot in the hub filler for receiving the tape leader pin. The hub filler is coupled to a guide arm that drives the hub filler along a guide rail between the single reel tape cartridge and the take-up reel. An example of a mechanism for driving the hub filler between the tape cartridge and the take-up reel is disclosed in U.S. Pat. No. 6,034,839.
FIG. 1 is a view of the tape drive loading mechanism disclosed in U.S. Pat. No. 6,034,839. The hub filler 300 enters into the removable cartridge 210 and attaches to the end of the tape. The hub filler 300 then moves along a guide rail 247, driven by the guide arm 250. Typically, the hub filler 300 attaches to the end of a tape in the tape cartridge 210 and the guide arm 250 moves the hub filler 300 along the guide rail 247, trailing the tape across the read/write head 222 and into the take-up reel 242. The hub filler 300 comprises a pin (not shown) fixedly attached to the bottom of the hub filler 300 that is in contact with the guide rail 247. More particularly, the hub filler 300 rides on the top of the guide rail 247 and is guided in the horizontal direction from the removable cartridge 210 to the hub 245 of the take-up reel 242. When the hub filler 300 enters the removable cartridge 210 to attach the end of the tape, the pin moves snuggly within the guide rail 247 at the cartridge to precisely control the position of the hub filler 300 during pick up of the tape. The tape is attached to the hub filler 300 and the hub filler 300 travels along the guide rail 247 between the removable cartridge 210 and the hub 245. During this movement, the pin is in contact with the inner surface of the guide rail 247. The hub filler 300 enters the take-up reel 245 through a channel 244 and into the hub 245 of the take-up reel 242.
FIG. 2 is a top view of the tape drive, depicting the hub filler 300 in the take-up reel 242 with the tape 216 attached. The tape 216 passes across the read/write head 222 and the end of the tape 216 is secured to the take-up reel 242. The tape drive is then operated by rotation of the take-up reel 242 and the single reel of the cartridge 210 about their respective axes to move the tape 216 across the read/write head 222. Motors are used to rotate the take-up reel 242 and the single reel of the cartridge 210, controlling the speed of the tape 216 as it moves across the read/write head 222. The hub filler 300 pivots on an axle 252 that is coupled to the guide arm 250. This pivoting is necessary for the hub filler 300 to be guided on the guide rail 247 into the take-up reel 242. Once the hub filler 300 is in the take-up reel 242, with the tape 216 attached, the take-up reel 242 rotates to thereby unload the tape from the cartridge 210. The hub filler 300 rotates with the take-up reel 242 on the axle 252. The loading mechanism attempts to align the axle 252 axis and the take-up reel 242 axis perfectly.
There are some concerns regarding the conventional tape drive loading mechanism described above. As the hub filler moves along the guide rail, only a small surface area of the pin is in contact with the inner surface of the guide rail. Consequently, there may be substantial friction between the guide rail and the pin. As a result, the pin becomes worn down as it travels repeatedly between the tape cartridge and the take-up reel.
The wearing down of the pin is a source of several problems in the conventional tape drive loading mechanism. One problem is that the wearing down of the pin reduces the accuracy with which the hub filler can pick up and drop off tape at the removable tape cartridge. The portion of the guide rail that is proximate to the removable cartridge needs to be arranged so the pin fits snugly in the guide rail. This is necessary so that the hub filler is tightly controlled and can accurately and repeatedly pick up the tape from the tape cartridge. However, if the pin is worn down, the pin will not fit snugly in this portion of the guide rail and the accuracy of the hub filler picking up the tape from the cartridge is diminished. This diminished accuracy increases the instances of the tape drive failing to load tape from removable cartridges, which compromises the reliability of the tape drive. Those skilled in the art will appreciate that the reliability of the tape pick-up and tape drop-off mechanism is an important characteristic of tape loading devices.
There is a need for a tape drive loading mechanism that guides a hub filler between a removable tape cartridge and a take-up reel substantially without friction.
These and other needs are met by embodiments of the present invention, which provide the implementation of a roller in place of the conventional pin at the bottom of the hub filler. More particularly, the present invention relates to a tape loading device for loading tape from a tape cartridge to a take-up reel. The device comprises a hub filler and a means for frictionless guiding of the hub filler between the tape cartridge and the tape-up reel. The hub filler is driven independent of the take-up reel.
With the present invention, the roller on the bottom of the hub filler substantially eliminates friction between the hub filler and the guide rail. As a result of this reduced friction, the roller experiences reduced wear. The roller is able to snugly fit within the portion of the guide rail proximate to the removable tape cartridge. The hub filler of the present invention can therefore more accurately pick up and drop off tape from the tape cartridge.